...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Repulsive versus attractive Hubbard model: Transport properties and spin-lattice relaxation rate
【24h】

Repulsive versus attractive Hubbard model: Transport properties and spin-lattice relaxation rate

机译：排斥性与吸引力的哈伯德模型：输运性质和自旋晶格弛豫率

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We contrast the transport properties (dc resistivity, Seebeck coefficient), optical conductivity, spectral functions, dynamical magnetic susceptibility, and the nuclear magnetic resonance 1 / T_1 spin-lattice relaxation rate of the repulsive and attractive infinite-dimensional Hubbard models in the paramagnetic phase for a generic band filling. The calculations are performed in a wide temperature interval using the dynamical mean-field theory with the numerical renormalization group as the impurity solver. The attractive case exhibits significantly more complex temperature dependencies which can be explained by the behavior of the half-filled Hubbard model in external magnetic field with constant magnetization, to which the attractive Hubbard model maps through the partial particle-hole transformation. The resistivity is nonmonotonous for the strongly attractive case: it peaks significantly above the Mott-Ioffe-Regel value at a temperature T_(max) where the quasiparticle band disappears. For both signs of U we find particle-hole asymmetry in the self-energy at low energies, but with the opposite kind of excitations having longer lifetime. This leads to a strong suppression of the slope of the Seebeck coefficient in the attractive case rather than an enhancement as in the repulsive case. The spin-lattice relaxation rate in the strongly attractive case has a nonmonotonic temperature dependence, thereby revealing the pairing fluctuations.
机译：我们对比了顺磁相排斥和有吸引力的无限维哈伯德模型的输运特性（直流电阻率，塞贝克系数），光导率，光谱函数，动态磁化率和核磁共振1 / T_1自旋晶格弛豫率用于通用乐队填充。使用动态平均场理论，在数值重归一化组作为杂质求解器的情况下，在宽温度区间内执行计算。有吸引力的情况下表现出明显更复杂的温度依赖性，这可以用半填充的Hubbard模型在具有恒定磁化强度的外部磁场中的行为来解释，有吸引力的Hubbard模型通过部分粒子-空穴变换映射到该行为。对于极具吸引力的情况，电阻率是非单调的：在准粒子带消失的温度T_（max）处，其峰值明显高于Mott-Ioffe-Regel值。对于U的两个符号，我们发现低能量时自能量中的粒子-孔不对称，但是相反类型的激发具有更长的寿命。这在有吸引力的情况下导致塞贝克系数斜率的强烈抑制，而不是在排斥情况下得到增强。在极具吸引力的情况下，自旋晶格弛豫速率具有非单调的温度依赖性，从而揭示了配对波动。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号